The Egyptian Series: Green Treasure

Are there emeralds still to be found at Sikait in the Mountains of the Eastern, Red Desert of Egypt bordering the Red Sea?

Donald Phipps, archaeologist, is fairly confident there must be some good stones left there although, since the time of Cleopatra two thousand years ago, nobody has really bothered to search for them. His 'patron', Solomon Hunter III, is arriving from New York, to see the stones. Where is Donald? He has vanished.
Donald's rogue brother, Alistair, comes to Egypt hoping to cash in on Don's fortune. He steals the stones that have already been found, bolts and is found dead. His brother tries to report him dead, but gets locked up himself. For 6 weeks nobody knows where he is; is he dead or what?
Don's daughter and nephew travel to Egypt searching for him. Nobody knows anything.

This story ranges from the Red Sea, East of the Nile, to the West Bank and the Valley of the Kings.